Answer:
• 

• 

Explanation:
To solve these questions, we need to rearrange the equations to make the unknown variables the subject of the equations. 
1a. 

⇒ 
 [multiplying both sides by 46]
 [multiplying both sides by 46]
⇒ 

1b.

⇒ 
 [multiplying both sides by d]
 [multiplying both sides by d]
⇒ 
 [multiplying both sides by 44]
 [multiplying both sides by 44]
⇒ 
 [dividing both sides by 68]
 [dividing both sides by 68]
⇒ 
